algorithmic modeling for Rhino
Hmm, it seems like a bug. In the meantime, you can make it work by Reparamaterizing the curves (upper left parameter in your file).
Maybe a slight calculation error by rounding.
If you use the "reparametrize" option on the curve inputs, it will work.
How do I know? First of all, reparametrizing did solve the problem. Further inspection shows that Params A is reparametrized from 1369.37... to 0.0 at list position 5. If you select only list item 5, Shatter will fail, all other list items seem to work.
Thanks for the detailed report, should help me find the bug.
But if I reparameterise I will lose the exact position, or not?
I left the file at the office... o/
Reparametrize does nothing more than rescale the curve parameters so they fit the interval of 0.0 to 1.0. Since the parameter in general is kind of arbitrary, that doesn't change anything with respect to exact position along the curve or in 3D space. Only the numeric value of the parameter will change... if you ignore possible bugs.